The present invention relates generally to clamping tools and more particularly to a tool and method for clamping two structures together with vacuum clamps and performing an operation on them.
In the manufacture of modern aircraft, it is fairly common to utilize automated riveting processes to fasten several components together. In such operations, a first component, such as a longeron, may be clamped into a fixture or jig so as to conform to a desired contour, while a second component, such as a skin, is clamped to the first component. Several holes are typically formed into the components and temporary fasteners are employed to retain the components together during the automated riveting process.
In many instances, the clamps that are employed to retain the second component to the first component, as well as the fixturing, may not be capable of exerting sufficient clamping force onto the components to eliminate gaps between the components during the forming of the holes for the temporary fasteners. Consequently, gaps are formed during the drilling process as a result of the various forces that are exerted onto the components (e.g., the force exerted by the cutting tool). Gaps between the components permit the chips that are formed during the drilling step to migrate between the components. As such, it is necessary that the components be off-loaded from the fixture, deburred, cleaned and re-loaded to the fixture prior to the installation of the temporary fasteners.
Accordingly, there remains a need in the art for a tool that can provide sufficient clamping force to the components so as to eliminate the formation of gaps between the components during a drilling operation.
In one preferred form, the present invention provides an apparatus for securing a first structure to a second structure and performing an operation on the first and second structures. The apparatus includes a frame structure, a plurality of suction cups, a clamp assembly, a conveyance mechanism and a tool. The plurality of suction cups are coupled to the frame structure and are operable in an energized mode for securing the apparatus to the first structure. The clamp assembly is coupled to the frame structure and exerts a clamping force onto the second structure when the suction cups have secured the apparatus to the first structure. The clamping force is of sufficient magnitude to retain the second structure in a predetermined position relative to the first structure. The tool is configured to perform the operation. The conveyance mechanism is coupled to both the frame structure and the tool and enables the tool to be selectively positioned relative to the frame structure.
In another preferred form, the present invention provides a method for coupling a first structure to a second structure. The method includes the steps of: providing a tool apparatus having a plurality of suction cups and a clamp assembly; energizing the plurality of suction cups to secure the tool apparatus to the first structure; employing the clamp assembly to exert a force onto the second structure that retains the second structure to the first structure; forming a hole through the first and second structures; inserting a fastener through the hole and fastening the first and second structures together; and removing the tool apparatus from the first structure after the first and second structures have been fastened together.
In yet another preferred form, the present invention provides an apparatus for securing a first structure to a second structure and performing an operation on the first and second structures. The apparatus includes a frame structure, a plurality of suction cups and a clamp assembly. The plurality of suction cups are coupled to the frame structure and operable in an energized mode that for securing the apparatus to the first structure. The clamp assembly is coupled to the frame structure and includes a fluid power cylinder having a rod that is movably coupled to the frame structure. The fluid power cylinder is operable in a first mode for moving the rod toward the second structure and exerting a clamping force that is of sufficient magnitude to retain a mating surface of the second structure against a mating surface of the first structure. The fluid power cylinder is also operable in a second mode for moving the rod away from the second structure.